Budgeting the Build of a 35' steel sailboat; worthwhile costs vs. extravagance

Discussion in 'Metal Boat Building' started by welder/fitter, Sep 12, 2010.

  1. pdwiley
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    pdwiley Senior Member

    Here in Tasmania a 4.2m3 tank of oxygen costs $70 AUD roughly and the bottle rental is $17/month. I don't have figures on argon as I haven't used any for a while. I use LPG as my fuel gas so no bottle rental.

    I can buy a gas cutting torch kit for approx $200 and a 50A plasma cutter for $600 but you also need a compressor at another $200-300 at least. Gas cutting is cheaper in the first cost but more expensive to run, though I go through quite a few plasma cutting tips. I need to add an air dryer to my system I think.

    No question in my mind that plasma cutting is the way to go on speed, accuracy and cleanliness of cut. You can make a template out of MDF (medium density fibreboard) and use it as a guide for the plasma torch, something impossible with gas cutting.

    PDW
     
  2. bearflag
    Joined: May 2010
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    bearflag Inventor/Fabricator

    I bought my plasma torch on craigslist, it easily chops thru an inch of steel, and I can dial it up to do more. I can't imagine having to go back to grinding, milling, or gas torching thru metal plates anymore.
     
  3. welder/fitter
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    welder/fitter Senior Member

    The reason I use the longer version is that the term MIG isn't really a correct term, as one uses more than inert gases with the process. I usually use both terms, however, so that there is less confusion. It's nothing to do with "being fancy".(lol)

    I'm glad that Wynand & you mentioned the difficulties in judging a MIG weld's penetration by it's appearance. I'll add that flux-core self-shielding(fcaw-ss) wire is also challenging for a lot of welders & really isn't worth using, unless it is all that is available, as it doesn't give one the speed that makes the wire processes so attractive.

    Mike
     
  4. welder/fitter
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    welder/fitter Senior Member

    #2 - Professional assistance - In discussions regarding the construction of steel boats, the concensus appears to be that the best-case scenario would be for the first-time amateur builder to employ a professional builder/yard to assemble the vessel.

    It is, however, appreciated that one can not, or does not wish to, do so, at times. The recommendation would then be for the builder to involve professionals to assist and/or advise in each phase of construction. While there is value in internet forums such as these, having a professional on-site is invaluable, as he/she will not only advise on the concerns the builder asks about, but will observe the entire project & point out problems which the builder may not have recognized as occuring. As the professional will be familiar with the local area, he/she should also have knowledge of which processes, equipment and materials are available in the area and which are the cheaper & more expensive alternatives. A further benefit of the involvement of an experienced individual is that he/she will keep the project on track and will give encouragement to the first-time builder, when needed. Too many such projects have gone unfinished due to a lack of direction and a subsequent loss of enthusiasm.

    In choosing a professional to advise/assist, it is suggested that the builder first consider a professional experienced in all aspects of steel boat construction, before one experienced in only one, two, or a few aspects.

    (change, restructure where necessary/prudent)
     
  5. wardd
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    wardd Senior Member

    I'm no welder so instead of welding plenty good, I weld good and plenty.

    I do all my welding outside and haul my welder on a garden cart so flux is the way for me
     

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  6. pdwiley
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    pdwiley Senior Member

    Yeah but that's like me saying that I bought my Colchester toolroom lathe loaded with tooling for $1000 off of the local craigslist equivalent. It may well be true (in fact it is) but it's totally unhelpful as the chances of someone else doing the same are very slim.

    Also to cut through 25mm of steel I'd expect it to be an 80A output unit. What sort of power supply does it need to feed it? The gear I quoted is adequate to do the cutting you need to build a small boat and available retail anywhere on the planet, pretty much.

    PDW
     
  7. welder/fitter
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    welder/fitter Senior Member

    I guess #3 should be location of build. I'll have to re-read the posts on location & see what to add to Peter's post that pretty much summed up the subject.
     
  8. pdwiley
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    pdwiley Senior Member

    it's also expensive.

    PDW
     
  9. Jack Hickson
    Joined: Jan 2011
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    Location: Vancouver Island BC

    Jack Hickson New Member

    There have en a lot of "Pro" Built boats here in BC I wouldn't advise anyone buying.
    Foulkes boats , like the Foulkes 39 have been built here for decades, 10 guage hull plate , including he keel, welded one side only ( outside) most of the weld ground off to make it look pretty, foam over mills cale inside, no paint of any kind under the foam, Fuel tank vents in the topsides, where they go under water when the boat heels, white delrin plastic thru hulls you can easily slap off with the palm of your hand. etc etc,
    Fehrs boats were similarly built.
    Don't count on how long they have been around as a giude, as they have been around and building them for decades. A consciencious amateur couldn't do any worse and 95% of the time do far better.
     
  10. welder/fitter
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    welder/fitter Senior Member

    I recall Brent Swain often making such comments, yet, having viewed 2 "Foulkes" and 3 Horizons in the past year, I see no indication of single-sided welding at the keel/hull joint, nor plastic thru-hulls nor did I notice a lack of hull paint in the insulated areas that were viewable, when checking for moisture/adhesion. I didn't notice fuel tank venting issues on the one boat that I recall considering such issues. Obviously, I can not comment on the mill scale.

    I'd suggest that the belief that 95% of amateur builders do far better than professionals is, at best, wishful thinking.

    Mike
     
  11. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    I agree.

    Probably most amateurs, since they do not work in the professional field, are not coded. So, what does that mean...simplistically they have no real bench mark to judge whether their weld is good or bad, other than their own thoughts on the matter. A visually pleasing weld is not enough. I can produce a half decent looking welds. But when subjected to bench mark tests and x-rays...was hopeless. Luckily it is not my day job! :eek:

    I've seen enough welds that "look visually" ok, but are filled with porosity and/or LOP/LOF. The causes are simple...inexperience in the set-up and procedure.

    The amateurs equates "..I'm taking my time, so I'm bound to do a good job..", with quality. If were only that simple.
     
  12. Jack Hickson
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    Jack Hickson New Member

    Amazon , back in the early 80s also built a lot of one side only welded boats, caled Amazon 37's . A friend said he visited the shop when one was waiting for the spray foamer. He could see inside the gap in the cabinside - cabin top seam almost 1/8th of an inch. It was welded outside only, and most of that weld ground off. A Kiwi I met, said his friend was hunting down the owner of the business with a law suit in hand .He found his longitudinals were held in by a half inch tack every three feet. When he caught up with the owner, the company filed for bankruptcy and that was the end of his claim for compensation.
    Anyone can walk down any dock with a Foulkes or Horizon and see white delrin thru hulls, and fuel tank vents in the topsides, well below the deck level.
    Both are so called "Profesionally" built boats, which have been built and sold in BC for decades.
    Waterline Yachts are the only properly welded, commercially built boats in BC that I'm aware of , good boats , but horrendously expensive.
    Cut a weld with a torch. If there is slag in, it wil spit back at you. If it cuts cleanly, it is solid metal.
     
  13. Ad Hoc
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    Ad Hoc Naval Architect

    That depends upon your definition of "professional".

    To an amateur, a professional is generally considered someone who welds for their daily job. But this is no indication of "quality" and "professionalism".

    I cook everyday, does that make me a professional chef??

    A professional welder, is one that has been properly trained, and had to take tests. They then have to show their competence by performing welding tests, at various thicknesses, and positions, such as down-hand or overhead.

    These tests pieces are sent for independent verification and x-ray to ascertain if the weld is a quality weld and that the minimum mechanical properties are maintained, for that material. Said welder then gets a "ticket" issued from the Classification authority, such as DNV or LR, stating said welder is certified to weld XXX material over YYY thicknesses using ZZZ techniques. This cert is valid for 2 years only.

    During their daily job, parts of their fabrication will be randomly checked by NDT and/or X-ray and inspected independently by the QA dept, and then by the surveyor of the Classification society to formally approve the fabrication.

    A professional welder always has a current cert, and is always vigilant on their procedures, whether the shipyard has a QA dept or not. They pride themselves on doing a quality job, whether someone tells them to do so or not. When they are doing a job..if something is not right or too difficult or they know will not produce a quality joint, for whatever reason, they ask advise or seek clarification. It's their name on the job, and their pride. A professional, in whatever job, knows their limits.

    I have tremendous respect for the "professional" welders i have known over the past 25 years. They have taught me a lot.

    There is a big gulf in quality between a person who welds everyday in their job and a proper professional welder.

    I can cook..but I'm no Jamie Oliver!
     
  14. scott hightower
    Joined: Jul 2010
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    Location: Georgia

    scott hightower Junior Member

    If your building a boat don't try it with a low buck buzz box. I would spend the extra cash on a quality welder. Since you are not likely to spend the money to xray your welds you better make sure you have a machine that will easily achieve full penetration and tie in all the welds.

    Scott
    Fab Manager
    Welders360.com
     

  15. pdwiley
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    pdwiley Senior Member

    I use a 40 year old 250A 'buzz box' welder and E4111 rods. I've welded coupons in all positions and cut them open to check penetration. I've no problems getting 100% penetration on typical plate thicknesses in small boats.

    While I have a nice MIG welder and I use it quite a lot I prefer the stick welder and cellulose rods for root runs. Old used AC welders like mine are available for peanuts. A new inverter type welder would likely be better but cost more.

    PDW
     
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